槲皮素对提高猪油抗氧化性的研究

本文讨论了天然物质——槲皮素、柠檬酸混合物作为食用油脂的抗氧化剂,加入猪油中对其氧化稳定性的影响。实验分三阶段进行:通过重量法实验,以油脂在常温条件下氧化诱导期为指标,研究油脂在常温条件下稳定性。通过煎炸实验,以油脂在高温条件下酸价、羰基值、茴香胺值、过氧化值的变化,研究油脂在高温条件下的水解、氧化劣变,通过煎炸食品储存,以酸价、过氧化值、羰基值为示踪指标,研究残油在含油食品中抗氧化剂对保持油脂氧化稳定性的作用.实验表明:槲皮素有较好的抗氧化能力,延长猪油的氧化诱导期约8～20倍,增加油脂常温储藏时间.这种混合抗氧化剂能延长煎炸油使用寿命,延长煎炸食品保存期.槲皮素、柠檬酸混合抗氧化剂抗氧化效果较资料介绍的其它抗氧化剂更为优良.     

迷迭香在油香椿制品储藏过程中的抗氧化效果研究

选用TBHQ、迷迭香和茶多酚等作为抗氧化材料,研究几种抗氧化剂对油香椿制品储藏过程中油脂氧化效果的影响.采用烘箱加热进行加速试验,定期测定油脂过氧化值(POV)的变化情况来研究不同浓度天然抗氧化剂迷迭香和添加维生素C、植酸或柠檬酸等增效剂的迷迭香抗氧化效果.实验结果显示:天然抗氧化剂迷迭香的抗氧化效果优于茶多酚,比TBHQ的抗氧化效果稍差,0.02%迷迭香能有效阻遏油脂中POV值的升高,它与维生素C、植酸或柠檬酸混合使用,能显著增强抗氧化作用.     

天然抗氧化剂对南极磷虾油抗氧化效果的研究

为了防止南极磷虾油在长期储藏过程中发生氧化酸败,品质下降。采用Schaal加速试验方法,以过氧化值(POV值)和茴香胺值作为油脂稳定性的评价指标,研究了3种天然抗氧化剂VE、迷迭香提取物以及抗坏血酸棕榈酸酯对南极磷虾油抗氧化性能的影响。结果表明,如果以茴香胺值作为评价指标,向磷虾油中添加3000mg/L的天然VE抗氧化效果最好;如果以过氧化值为评价指标,向磷虾油中添加3000mg/L的迷迭香提取物抗氧化效果最好。综合抗氧化剂的价格成本以及国家对食品添加剂的限量标准两方面因素,最后选择添加3000mg/L天然VE作为南极磷虾油的抗氧化剂配方。     

不同油脂及抗氧化剂对韧性饼干氧化变质的影响

本文研究了不同油脂及抗氧化剂对于韧性饼干在65℃下氧化变质的影响。通过测定该饼干在65℃保存下酸价、过氧化值、水分含量以及感官评分四项指标的变化,确定饼干氧化变质的速度。试验发现饼干中添加黄油时四项指标变化最为缓慢,65℃下可保存54 d;添加豆油时四项指标变化相对较快,65℃下可保存48 d。看来饱和脂肪酸含量高的油脂的氧化速度较慢,制作出的饼干变质慢,保质期长;不饱和脂肪酸含量高的油脂的氧化速度较快,制作出的饼干变质快,保质期短。所有抗氧化剂都具有抗氧化效果:合成抗氧化剂中TBHQ的效果最好,天然抗氧化剂中茶多酚的效果最好;当0.010%TBHQ结合0.020%茶多酚复配使用时,抗氧化效果最明显,氧化变质最慢,饼干在65℃的储藏下可保存60 d。因此,不同油脂及抗氧化剂对饼干的氧化变质都有影响。该研究为延长饼干的保质期提供参考。     

鼠尾草酸对煎炸条件下玉米油品质裂变的影响

采用玉米油为原料,模拟煎炸条件,研究鼠尾草酸对油脂的抗氧化作用。实验采用可见分光光度法研究鼠尾草酸的抗氧化活性,模拟高温煎炸条件研究玉米油的品质变化。结果表明:当鼠尾草酸添加量为0.5 mg/mL时,抗氧化活性最优。通过测定高温煎炸条件下玉米油酸价、过氧化值、丙二醛值,反式脂肪酸含量等表明,随着加热温度的升高,或者煎炸时间增加,各项指标上升,氧化速度加快,鼠尾草酸的加入能有效减缓油脂品质裂变。     

抗氧化剂对油脂煎炸稳定性的影响研究进展

煎炸过程中,油脂会发生水解、氧化、聚合等一系列化学反应,其中一些反应产物影响着油脂和煎炸食品的安全、健康和保质期。抗氧化剂可以有效抑制油脂的氧化,提高油脂的煎炸稳定性。油脂的煎炸稳定性通常通过测定极性组分、过氧化值、酸价、不饱和脂肪酸以及有害物质的含量等进行评价。结合近年来国内外抗氧化剂应用于油脂的最新研究,系统阐述了抗氧化剂对油脂煎炸稳定性的影响,同时总结了抗氧化剂在油脂煎炸过程中的变化,最后提出抗氧化剂在实际应用中面临的问题,以期为抗氧化剂尤其是天然抗氧化剂在油脂中的应用提供参考。     

天然复合抗氧化剂对精炼栀子果油抗氧化性影响

目的 比较不同抗氧化剂对精炼栀子果油的抗氧化效果,确定天然复合抗氧化剂复合配方,探究天然复合抗氧化剂在煎炸条件下对精炼栀子果油的保护作用。方法 以精炼栀子果油为原料,比较天然抗氧化剂（葡萄籽提取物、茶多酚、茶多酚棕榈酸酯、抗坏血酸棕榈酸酯、迷迭香提取物）和合成抗氧化剂（dl-α-生育酚、BHT、TBHQ）与精炼栀子果油结合前后的自由基清除能力及对油脂Pf值的影响;通过D-optimal设计分析确定天然复合抗氧化剂复合配方;在160℃条件下,考察添加了TBHQ和天然复合抗氧化剂后精炼栀子果油的过氧化值、羰基价、茴香胺值和主要脂肪酸变化规律。结果 茶多酚棕榈酸酯、抗坏血酸棕榈酸酯、迷迭香提取物与精炼栀子果油结合后能更好的发挥其自由基清除能力,提高油脂Pf值,茶多酚在提高油脂Pf值方面也具有显著效果;天然复合抗氧化剂复合配方为茶多酚0.1 g/Kg+茶多酚棕榈酸酯0.15 g/Kg+抗坏血酸棕榈酸酯0.05 g/Kg+迷迭香提取物0.18 g/Kg;添加天然复合抗氧化剂后对精炼栀子果油的过氧化值、羰基价的抑制效果均好于TBHQ,对茴香胺值抑制效果与TBHQ相当,对多不饱和脂肪酸具有良好的保护效果。结论 天然抗氧化剂在精炼栀子果油中的抗氧化效果良好,添加天然复合抗氧化剂后精炼栀子果油具有很好的氧化稳定性。     

5种精制食用油在煎炸薯条过程中的品质变化

以大豆油、菜籽油、棕榈液油、棉籽油和煎炸调和油为研究对象,以薯条为煎炸原料,通过研究5种精制食用油在高温煎炸过程中理化指标的变化,从而反映出不同精制食用油在煎炸过程中品质的变化。结果表明:色泽可以作为一个最直观的指标反映食用油的煎炸程度;用酸值来评价煎炸油的品质具有滞后性和多变性;过氧化值的高低并不能完全反映油脂的煎炸程度,仅可作为判断食用油煎炸品质的参考指标;羰基值随着煎炸时间的延长整体呈线性正相关趋势,说明羰基值是一个判断煎炸油热劣变程度的灵敏指标;5种精制食用油一旦经过煎炸,氧化诱导时间迅速缩短,与油脂的煎炸程度没有很好的相关性,因此氧化诱导时间不能作为评价油脂煎炸品质的可靠指标;极性组分的含量是评价煎炸油热劣变程度的可靠手段之一。在煎炸过程中,棕榈液油的煎炸稳定性明显高于其他4种食用油。     

牡丹籽油脂肪酸成分分析及其抗氧化性能研究

采用气相色谱-脂肪酸甲脂法对牡丹籽油的脂肪酸成分进行分析。结果表明,牡丹籽油不饱和脂肪酸含量高为91.73%,其中油酸含量为22.83%,亚油酸含量为26.69%,亚麻酸含量为42.21%。通过加速氧化的方法对不同抗氧化剂对牡丹籽油的抗氧化保护作用进行了研究。结果表明,选用的抗氧化剂显著抑制牡丹籽油中亚麻酸的氧化速度,抑制牡丹籽油过氧化值的效果顺序为TBHQV_E茶多酚,抑制油脂茴香胺值的效果顺序为V_ETBHQ茶多酚,抑制脂肪酸败值的效果顺序为TBHQ茶多酚V_E。由于茶多酚、V_E为天然抗氧化剂,且抗氧化效果与TBHQ相比相差不大,因此,选用天然抗氧化剂茶多酚、V_E代替传统的抗氧化剂TBHQ,在牡丹籽油的长期储存过程中具有良好的应用前景。     

食用大豆油储藏过程中品质变化的预测

以一级大豆油为原料,储藏温度设定为40 ℃,研究储藏时间、抗氧化剂用量、水分含量对其品质的影响。在单因素试验的基础上,以储藏时间、抗氧化剂用量、水分含量3 个因素为自变量,大豆油品质指标（过氧化值和氧化稳定指数）为响应值,采用响应面Box-Behnken试验设计法,建立了大豆油品质随储藏时间、抗氧化剂用量、水分含量变化的二次多项式预测模型。结果表明：储藏时间、抗氧化剂用量、水分含量对大豆油的过氧化值和氧化稳定性指数的影响显著;大豆油品质指标预测模型的方差分析表明,模型皆极显著（P＜0.001）,实验误差小,可以此模型来预测大豆油过氧化值和氧化稳定指数随储藏时间、抗氧化剂用量、水分含量的变化,具有较高的拟合优度。     

Biological activity of Boswellia serrata Roxb. oleo gum resin essential oil: effects of extraction by supercritical carbon dioxide and traditional methods

The findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.     

Physico-Chemical Properties,Composition, and Oxidative Stability of Olive and Soybean Oils Under Different Conditions

Commercial olive and soybean oils have been analyzed periodically in order to evaluate the influence of storage conditions on quality. The following parameters were determined every 10 days of storage: peroxide, saponification and acid values, absorption coefficients K₂₇₀ and K₂₃₂, phenols, chlorophylls and carotenoids contents, DPPH scavenging ability, and total antioxidant activity. Edible oils were exposed to daylight and stored at room temperature in different containers with the same surface area of exposure to air either in clear glass or opaque glass bottles. Changes in oils properties were also examined after the addition of Vit-E as an antioxidant in oil samples. The results showed a gradual loss of quality during storage, especially in clear glass bottles. The addition of the antioxidant, however, significantly reduced the deterioration and oxidation rate in the oil. The best containers for commercial packing of oil were opaque glass bottles containing antioxidant products.     

天然精油协同等离子体对盐水鸭杀菌保鲜及脂质氧化的调控

为调控等离子体处理对肉类造成的脂质氧化现象，研究复合精油协同低温等离子体（cold plasma，CP）处理对盐水鸭保鲜及脂质氧化的影响。采用牛至精油、肉桂精油和迷迭香配制复合精油，研究CP处理对复合精油抑菌性、总酚含量和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基清除率的影响。此外，将复合精油协同CP处理盐水鸭，对18 d贮藏期内盐水鸭的菌落总数、大肠杆菌菌落数、色泽及脂质氧化进行测定。结果表明：CP处理未对复合精油的总酚含量和DPPH自由基清除率造成显著影响，但当复合精油质量分数为0.100%～0.125%且协同CP处理大肠杆菌菌液时，大肠杆菌菌落数可降低8（lg（CFU/mL））；同时，复合精油协同CP处理可使盐水鸭保质期显著延长，且对盐水鸭的色泽无显著影响，并能使样品硫代巴比妥酸反应物值从CP处理组的6.87 mg/kg降至4.58 mg/kg。     

基于气相色谱-静电场轨道阱高分辨质谱的四种植物精油成分分析及其抗氧化活性评价

采用气相色谱-静电场轨道阱高分辨质谱联用仪（GC-Orbitrap-MS）对不同来源的辣椒精油、姜黄精油、香茅精油和小茴香精油的成分进行确定,通过谱库比对的正/反向匹配度和保留指数（retention index,RI）,共同确证未知化合物,峰面积归一化法计算相对含量,同时运用电子鼻技术对植物精油进行快速鉴别,测定DPPH、ABTS自由基清除率及总抗氧化能力,比较其体外抗氧化活性。结果表明:辣椒精油鉴定出33种化合物,主要成分为辣椒碱类化合物;姜黄精油鉴定出95种化合物,主要成分为姜烯、长叶烯等倍半萜化合物;香茅精油鉴定出137种化合物,主要成分为香茅醛、香茅醇、丁香烯等;小茴香精油鉴定出56种化合物,主要成分为反式茴香脑。电子鼻可对不同来源精油进行快速区分,经电子鼻雷达图分析表明W1W、W2W和W5S三个传感器对区别不同来源的精油挥发性成分发挥了关键作用。根据DPPH、ABTS自由基清除率和铁离子还原抗氧化能力（FRAP）检测结果,抗氧化活性从强到弱依次为姜黄精油,香茅精油,辣椒精油,小茴香精油,以来源三的姜黄精油抗氧化活性最强,DPPH、ABTS自由基的半数清除率以及FRAP值分别为1020.99 μL/L、464 μL/L、44.72 μmol Trolox/mL。GC-Orbitrap-MS分析技术可对植物精油的挥发性成分进行全面分析,为植物精油在食品行业中的深入开发提供理论依据。     

Effect of the Addition of Basil Essential Oil on the Degradation of Palm Olein during Repeated Deep Frying of French Fries

The potential antioxidant power of basil essential oil under frying conditions was explored. Two concentrations (200 or 500 ppm) were added to palm olein (PO) to evaluate their effect on fat oxidation/degradation during repeated frying of French fries at 180 °C. A higher oxidative stability index was detected for PO with basil essential oil at 200 ppm. Both concentrations showed lower p‐anisidine values than PO without basil essential oil after 5 d of frying. Addition at 500 ppm resulted in the lowest total polar compounds and free fatty acids contents. Thus, the addition of basil essential oil improved the performance of PO during repeated frying of French fries.     

大型罗勒和柚子精油的成分分析及其抗氧化性

采用气相色谱-质谱(GC-MS)联用法对大型罗勒精油和柚子精油的化学成分进行分析,并采用DPPH自由基(DPPH·)清除法、ABTS自由基阳离子(ABTS⁺·)清除法对精油及其主要单体的抗氧化性能进行了研究。大型罗勒精油鉴定出46个化学成分,占总含量的84.07%,其主要成分为香叶醛(14.20%)、β-石竹烯氧化物(10.97%)、香橙醛(10.38%)和β-石竹烯(4.09%);柚子精油鉴定出48个化学成分,占总含量的92.24%,其主要成分为柠檬烯(43.88%)、石竹烯(22.09%)、葎草烯(4.57%)和γ-松油烯(4.41%)。结果表明,大型罗勒精油和柚子精油对DPPH·和ABTS⁺·均具有清除活性,其中大型罗勒精油和柚子精油清除DPPH·的IC₅₀值分别为3.96 mg/mL和23.22 mg/mL;清除ABTS⁺·的IC₅₀值分别为1.61 mg/mL和2.30 mg/mL。由此可知,大型罗勒精油和柚子精油可以作为一种较为安全的天然抗氧化物来源。     

Synergetic Use of Principal Component Analysis Applied to Normed Physicochemical Measurements and GC × GC‐MS to Reveal the Stabilization Effect of Selected Essential Oils on Heated Rapeseed Oil

Lipid oxidation leads to the formation of volatile compounds and very often to off‐flavors. In the case of the heating of rapeseed oil, unpleasant odors, characterized as a fishy odor, are emitted. In this study, 2 different essential oils (coriander and nutmeg essential oils) were added to refined rapeseed oil as odor masking agents. The aim of this work was to determine a potential antioxidant effect of these essential oils on the thermal stability of rapeseed oil subject to heating cycles between room temperature and 180 °C. For this purpose, normed determinations of different parameters (peroxide value, anisidine value, and the content of total polar compounds, free fatty acids and tocopherols) were carried out to examine the differences between pure and degraded oil. No significant difference was observed between pure rapeseed oil and rapeseed oil with essential oils for each parameter separately. However, a stabilizing effect of the essential oils, with a higher effect for the nutmeg essential oil was highlighted by principal component analysis applied on physicochemical dataset. Moreover, the analysis of the volatile compounds performed by GC × GC showed a substantial loss of the volatile compounds of the essential oils from the first heating cycle.     

Pan-frying of French fries in three different edible oils enriched with olive leaf extract: Oxidative stability and fate of microconstituents

Sunflower oil, olive oil, and refined palm oil were enriched with an extract - rich in polyphenols - obtained from olive tree (Olea europaea) leaves at levels of 120 and 240 mg total polyphenols per kg oil. Potatoes were pan-fried in both the enriched and the non-supplemented oils under domestic frying conditions. Total polyphenols were estimated by Folin-Ciocalteu and antioxidant capacity was assessed by the DPPH radical scavenging assay. Tocopherols' content was determined by HPLC analysis, phytosterols and squalene by GC, and oxidative stability by Rancimat. Supplemented frying oils had higher total polyphenols and tocopherols' content, oxidative stability, and antioxidant capacity, while phytosterols and squalene content were not affected by the supplementation. French fries prepared in supplemented oils had higher total polyphenols, tocopherols, phytosterols, and squalene content and exhibited higher antioxidant capacity than those fried in non-supplemented oils. By consuming French fries pan-fried in enriched oils, up to 1.4-, 2.2-, and 1.5-fold increase of tocopherols, phytosterols, and squalene intake could be achieved as compared to those prepared in the non-supplemented oils.     

Effect of oregano and rosemary essential oils on lipid oxidation of stored frozen minced gilthead sea bream muscle

The study aimed to determine the effect of oregano and rosemary essential oils addition to minced gilthead sea bream muscle on lipid oxidation during frozen storage. Each essential oil was added to minced fish muscle at 500 mg/kg concentration which then was stored at ?22 °C for 12 months. Oregano essential oils inhibited the formation of conjugated diene and triene hydroperoxides and thiobarbituric reactive substances when compared with untreated samples after the first month and rosemary essential oils after the first and third month of frozen storage. Oregano and rosemary essential oils could be used as ingredients to prevent oxidation in stored frozen minced gilthead sea bream muscle, when long term preservation is not needed. The rate of lipid oxidation depends on antioxidant source. The rosemary essential oil proved to be more efficient in preventing lipid oxidation of minced gilthead sea bream muscle than oregano essential oil.     

Stabilizing Oils from Smoked Pink Salmon (Oncorhynchus gorbuscha)

ABSTRACT:  Smoking of meats and fish is one of the earliest preservation technologies developed by humans. In this study, the smoking process was evaluated as a method for reducing oxidation of pink salmon ( Oncorhynchus gorbuscha ) oils and also maintaining the quality of oil in aged fish prior to oil extraction. Salmon heads that were subjected to high temperatures (95 °C) during smoking unexpectedly produced oils with fewer products of oxidation than their unprocessed counterparts, as measured by peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and fatty acids (FA). Higher temperatures and longer smoking times resulted in correspondingly lower quantities of oxidative products in the oils. Fatty acid methyl ester (FAME) analysis of smoke-processed oils confirmed that polyunsaturated fatty acids (PUFA) were not being destroyed. Smoke-processing also imparted antioxidant potential to the extracted oils. Even when antioxidants, such as ethoxyquin or butylated hydroxytoluene, were added to raw oils, the smoke-processed oils still maintained lower levels of oxidation after 14 d of storage. However, decreased antioxidant capacity of smoke-processed oils was noted when they were heated above 75 °C. Vitamin studies supported the antioxidant results, with smoke-processed oils displaying higher levels of α-tocopherol than raw oils. Results suggest that smoking salmon prior to oil extraction can protect valuable PUFA-rich oils from oxidation. Improved preservation methods for marine oils may extend their usefulness when added as a supplement to enhance levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in foods.